There are studies, and there are studies. A lot of medical news reported in the media turns out to be based on studies of relatively small groups of people. That doesn’t mean that the findings aren’t real or relevant, but it does mean they carry less weight. What’s valued even less is “anecdotal” evidence, which means just what it says. Anecdotes, or individual stories, about some health impact or other. Not measured against larger results, anecdotal reports don’t often lead to serious health recommendations.
Epidemiologists are your friends
The gold standard for public health policy research is when data is analysed about large numbers of people who are evaluated by the same criteria. The scientists who study large patterns of health risks (and how to reduce them) are called epidemiologists.
Epidemiology researchers at Sungkyunkwan University School of Medicine in Seoul, South Korea have discovered a clear pattern of early heart disease risk related to sleep. They looked at the data of more than 47,000 young and middle-aged adults who completed a sleep questionnaire and whose hearts were tested for early coronary artery lesions or stiffening.
You might easily guess that a habit of sleeping too little (five hours or less) could damage your heart. But surprisingly, too MUCH sleep (nine or more hours) on a regular basis can harm it even more. Perhaps that partially explains the link between depression and increased heart disease risk, as well. Many people with depression have trouble sleeping, and others tend to oversleep.
Don’t skimp—but don’t binge, either
Calcium, the body’s most abundant mineral, doesn’t belong in your heart. Though it’s stored in bones and blood, normally it won’t enter the heart’s cells and vessels. But when inner artery walls have been damaged from the usual culprits (smoking, high cholesterol or blood pressure, and so on), wastes such as calcium, platelets, and fats can build up inside the artery. This reduces blood flow and raises the risk of heart attack. One way doctors test for early signs of heart disease is through scans that reveal calcium deposits.
In the South Korean study, the heart scans of adults who slept five or fewer hours a day showed they had 50 percent more calcium in their coronary arteries than the people who slept seven hours a day. And the long sleepers? Those who slept nine or more hours had over 70 percent more coronary calcium.
Here’s the simple takeaway. About seven hours of regular sleep per night is an optimal amount. Don’t worry about some variation, but keep in mind that routinely skimping or bingeing on sleep may be putting your heart at risk.
Moderation in all things, even sleep, will help keep your heart healthy.
Sleep quality counts
The calcium connection applies to how well you sleep, too, not just how little or how long. The adults who reported sleeping poorly during the night had more than 20 percent more coronary calcium than those who reported that they slept well.
The researchers found a similar pattern for arterial stiffness or hardening. People who didn’t get enough deep, restful sleep had stiffer arteries than those who slept well, or who slept seven hours nightly.
It’s about priorities
Because sleep is a quiet thing and our culture is so driven, it can be tempting to decide that because you’ve found that you can function without regular, good-quality sleep for an appropriate amount of time, you should.
But that way of thinking can come back to bite you.
No matter how many more tasks and to-dos you can accomplish by skimping on sleep (or how many will be left undone if you sleep too much)—it’s time to put a steady, seven-hour sleep habit right up there with diet, exercise, and stress reduction.
Healthful, normal sleep is your heart’s best friend. So do all you can to make it a newly-serious priority in your life. You’ll likely miss a few TV shows if your pattern has been to sacrifice getting enough sleep, or miss dozing the morning away if you’ve escaped into dreams too often. But straightening out your sleep routine means you’ll live a longer and healthier life.
Need some encouragement?
There’s nothing like a sublime natural mattress and a fresh, natural bedroom decor to make sleeping right a much easier choice. Whatever it takes, make your sleep zone more comfortable, healthful and inviting, and try to get your zzzzs in order.
You deserve the right amount of regular rest. Just listen to your heart.